This is one of the most asked questions regarding HTN. Why does the MD order one drug over the other?
I am a RN and from my perspective, the more accurate a pts history is and the more thorough the physical is, the greater the chance that the appropriate medication is prescribed.
Part of my job is to always act as a pt advocate AND also support the MD. In some cases, certain medications have been prescribed at dosages that are not indicated for the pts presenting symptoms and I have not hesitated to relay that information to the MD.
Having worked on PCU for many years, having a great RN or LPN with a good understanding of the effects of say calcium channel blockers vs beta blockers and why or why not they should be prescribed, can be a God-send to the doctor who is now on hour 18 of no rest and no sleep.

I even had one episode in the ER, in which a Cardiologist bounced some ideas on how to best admin Lasix in a diuresis of a very fragile renal failure pt. I felt honored to assist the MD in coming up with the most appropriate method to administer it. I told him that we could IVP the Lasix in 100cc NS at the rate that he stated that it must be administered.
In the end the pt tolerated the Lasix quite well without any adverse renal complications and the desired effect was obtained.
I am looking forward to seeing the GCP, as I am always interested in the different perspectives that one physician will have over another.